System and method for providing encryption for rerouting of real time multi-media flows

ABSTRACT

A system for providing encryption for the rerouting of multi-media data flow packets is disclosed. Generally, a first endpoint is connected to a second endpoint, wherein the first endpoint comprises a transceiver, encryption software stored within the first endpoint defining functions to be performed by the first endpoint, and a processor. The processor is configured by the encryption software to perform the steps of: assigning a sequence number to a first multi-media data flow packet received by a first endpoint, wherein the first multi-media data flow packet is within a series of multi-media data flow packets; pseudo-randomly shuffling the sequence number of the first multi-media data flow packet; and, transmitting the pseudo-randomly shuffled sequence number to a second endpoint. These steps may be performed by a programmed controller, or other hardware, instead of, or in addition to, being performed in accordance with software.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. patent application entitled“System and Method for Determining Flow Quality Statistics for Real-TimeTransport Protocol Data Flows,” filed on Jul. 23, 2001, and having Ser.No. 09/911,256, and U.S. Application entitled “System and Method forProviding Rapid Rerouting of Real-Time Multi-media Flows,” filed on Jul.23, 2001, and having Ser. No. 09/911,304, the disclosures of which areincorporated by reference herein in their entirety.

FIELD OF THE INVENTION

The present invention relates generally to the transmission ofmulti-media data packets, and more particularly to the encryption ofmulti-media data packets.

BACKGROUND OF THE INVENTION

The public switched telephone network (PSTN) has evolved into anefficient real-time, multi-media communication session tool whereinusers can pick up any one of nearly one billion telephones and dial anyone of nearly one billion endpoints. Several developments have enabledthis automated network, such as numbering plans, distributed electronicswitching and routing, and networked signaling systems.

Similar to the manner in which the PSTN is based on a hierarchy, theInternet is based on an Internet protocol (IP). IP messages are routedor forwarded from one link to the next (i.e., from a source of a dataflow to a destination of the data flow). Each IP packet contains an IPaddress, which, in Internet protocol version 4 (IPv4), has 32 bits. EachIP address also has a certain number of bits dedicated to a networkportion and a certain number of bits dedicated to a host portion.

IP routers are used to take a data packet from one network (or link) andplace it onto another network (or link). Tables are located within IProuters that contain information or criteria used to determine a bestway to route the data packet. An example of this information may be thestate of network links and programmed distance indications. By usingintelligent devices on both sides of a network domain, it is possible toallocate a temporary address to route a packet through a network andrestore the original address on the far side of the network when thepacket leaves the network. This is the basis for many current virtualprivate network (VPN) products and is understood in the art.

To ensure that the network elements (e.g., switches in the telephonenetwork, routers in the data network) can perform their associatedtasks, it helps for them to know the status of adjacent communicationlinks and available routes; signaling systems are used to provide thisinformation. In telephone networks, signaling systems used are eitherSS7 or are equivalent to SS7. The signaling system provides informationabout individual links, link sets, routes, etc. In data networks,protocols such as border gateway protocol (BGP), interior gatewayprotocol (IGP), open shortest path first (OSPF), etc., are used todetermine link states and routes.

Due to most current telecommunication endpoints receiving servicethrough a PSTN-based system, a gateway is used to facilitate amulti-media data flow between a packet data network and a PSTN. Gatewaysare installed at edges between data networks and voice networks, whereinthe gateways are used to convert multi-media (and signaling) to ensurecommunication. There are several strategies for routing calls receivedby gateways to other gateways described in the art. Two of thesestrategies are full mesh routing and hierarchical routing. Full meshrouting is the standard method described in most of the softswitchingarchitectures. Session initiation protocol (SIP) is the inter-softswitchsignaling system because it supports an anywhere-to-anywhere signalingmodel. In this model, softswitches have a virtual connection to othersoftswitches for completing calls. Routing tables are instantiated thatcan be used to direct traffic to a softswitch based on policy providedby the softswitch maker.

Unfortunately, when running a network that comprises many softswitches,the owner of the network has many different points of policy managementthat need to be maintained to create a full mesh. Such policy managementissues include assuring that each softswitch knows the IP address ofeach other softswitch and what telephone numbers or PSTN to which theyconnect. When running softswitches from multiple vendors, furthermanagement issues arise. The management issues are then more complicateddue to the fact that the equipment may be managed through differentinterfaces.

When the number of softswitches deployed grows large, the sharing ofdifferent routes is likely. In the full mesh routing arrangement, therouting of calls may be difficult since several different egresssoftswitches may be full or not functioning. For example, if a carrierhas thirty softswitches that can handle national long distance, and thenetwork is running at about 50% full, then each originating softswitchwill likely have to try an average of fifteen (15) separate softswitchesbefore finding one with a non-blocked route. This search effort can begreatly reduced if a purely random distribution is implemented, however,it is assumed that some routes would be preferred over others due tocost or quality, thereby exacerbating the problem.

Therefore, guiding real-time packet flows, such as, but not limited to,multi-media flows, through certain thresholds, which is required tocreate a high-quality border between various IP networks, is important.Without proper guidance, the packets would flow whichever way thenetworks would allow, thereby subjecting multi-media data packets todisruptive paths, as well as upstream and downstream failures.

If a guided multi-media data flow is traversing over public networks, itis desirable to prevent any person from eavesdropping on thecommunication. To address this issue, signaling channels can beencrypted using transport layer security (TLS), however, there is noknown mechanism for encrypting multi-media data packets. Endpoints areassumed to comprise functionality to perform encryption. This isproblematic in a network where sessions are routed to destinations suchas telephone numbers. The problem is that the actual termination pointis unknown until it is discovered. As an example, there may be multipledifferent termination points possible for a particular communicationsession. The actual termination point chosen may be selected fordifferent reasons. Therefore, when forward routing a communicationsession, the actual terminating equipment is not known in advance.

Specific reasons for problems associated with encryption are based oncurrently used mechanisms. As an example, a certificate ofauthentication, and a certificate of authority are generally used in themost advanced forms of encryption. The volume and delays associated withusing certificate servers are significant. It may also be the case thatusing manually distributed private keys could work, however, this is thecase if the number of destinations are limited to a known set in advancewhich would facilitate the distribution.

SUMMARY OF THE INVENTION

In light of the foregoing, the preferred embodiment of the presentinvention generally relates to a system and method for providingencryption for rerouting multi-media data flow packets.

Generally, with reference to the structure of the encryption system, thesystem utilizes a first endpoint, which is connected to a secondendpoint, wherein the first endpoint comprises a transceiver, encryptionsoftware stored within the first endpoint defining functions to beperformed by the first endpoint, and a processor. The processor isconfigured by the software to perform the steps of: assigning a sequencenumber to a first multi-media data flow packet received by a firstendpoint, wherein the first multi-media data flow packet is within aseries of multi-media data flow packets; pseudo-randomly shuffling thesequence number of the first multi-media data flow packet; and,transmitting the pseudo-randomly shuffled sequence number to a secondendpoint.

The encryption system may instead be provided completely in hardwarewherein functionality defined by the software is instead provided by acontroller that is programmed to perform the steps of: assigning asequence number to a first multi-media data flow packet received by afirst endpoint, wherein the first multi-media data flow packet is withina series of multi-media data flow packets; pseudo-randomly shuffling thesequence number of the first data flow packet; and transmitting thepseudo-randomly shuffled sequence number to a second endpoint.

The present invention can also be viewed as providing a method forproviding encryption for rerouting multi-media data flow packets. Inthis regard, the method can be broadly summarized by the followingsteps: assigning a sequence number to a first multi-media data flowpacket received by a first endpoint, wherein the first multi-media dataflow packet is within a series of multi-media data flow packets;pseudo-randomly shuffling the sequence number of the first multi-mediadata flow packet; and transmitting the pseudo-randomly shuffled sequencenumber to a second endpoint.

Other features and advantages of the present invention will be or willbecome apparent to one with skill in the art upon examination of thefollowing drawings and detailed description. It is intended that allsuch additional systems, methods, features, and advantages be includedwithin this description, be within the scope of the present invention,and be protected by the accompanying claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be better understood with reference to the followingdrawings. The components of the drawings are not necessarily to scale,emphasis instead being placed upon clearly illustrating the principlesof the present invention. Moreover, in the drawings, like referencednumerals designate corresponding parts throughout the several views.

FIG. 1 is a block diagram that illustrates a communication network,wherein the use of session routers and multi-media routers isdemonstrated, for implementation of the present encryption system.

FIG. 2 is a block diagram illustrating the use of three multi-mediarouters instead of the two shown by FIG. 1, in accordance with analternate embodiment of the invention.

FIG. 3 is a block diagram further illustrating a multi-media router,such as the first or second multi-media router of FIG. 1, which may beused for purposes of providing encryption capabilities within thecommunication network of FIG. 1.

FIG. 4 is a flow chart illustrating operations performed by the presentencryption system to provide encryption of multi-media data packetstransmitted within RTP flows.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention provides an encryption system for encryptingmulti-media data flow packets. The encryption system of the presentinvention can be implemented in software, firmware, hardware, or acombination thereof. In the preferred embodiment of the invention, whichis intended to be a non-limiting example, a portion of the encryptionsystem is implemented in software that is executed by a computer, forexample, but not limited to, a personal computer, workstation,minicomputer, or mainframe computer.

The software portion of the encryption system, which comprises anordered listing of executable instructions for implementing logicalfunctions, can be embodied in any computer-readable medium for use by,or in connection with, an instruction execution system, apparatus, ordevice such as a computer-based system processor-containing system, orother system that can fetch the instructions from the instructionexecution system, apparatus, or device and execute the instructions. Inthe context of this document, a “computer-readable medium” can be anymeans that can contain, store, communicate, propagate or transport theprogram for use by or in connection with the instruction executionsystem, apparatus or device. The computer-readable medium can be, forexample, but not limited to, an electronic, magnetic, optical,electromagnetic, infrared, or semiconductor system, apparatus, device,or propagation medium. More specific examples (a non-exhaustive list) ofthe computer-readable medium would include the following: an electricalconnection (electronic) having one or more wires, a portable computerdiskette (magnetic), a random access memory (RAM) (magnetic), aread-only memory (ROM) (magnetic), an erasable programmable read-onlymemory (EPROM or Flash memory) (magnetic), an optical fiber (optical),and a portable compact disk read-only memory (CD ROM) (optical). Notethat the computer-readable medium could even be paper or anothersuitable medium upon which the program is printed, as the program can beelectronically captured, via for instance, optical scanning of the paperor other medium, then compiled, interpreted or otherwise processed in asuitable manner, if necessary, and then stored in a computer memory.

In the transmission of multi-media data packets from a first endpoint toa second endpoint the processing of multiple transmission routes, andthe selection of a best route, is desirable. An example of a system thatprovides for route processing and selection is provided by theco-pending U.S. patent application entitled, “System and Method forAssisting in Controlling Real-time Transport Protocol Flow ThroughMultiple Networks via Multi-media Flow Routing,” by MeLampy, et. al,filed on Jul. 23, 2001, and having Ser. No. 09/911,256 (hereinafter,“the '256 patent application”), the disclosure of which is herebyincorporated by reference in its entirety.

The '256 patent application teaches use of a session router to selectmultiple routes and process them in order, selecting from a set ofsession initiation protocol (SIP) agent(s) that are otherwise equalusing various distribution strategies. This process leads to managingthe path of the resulting real-time packet (RTP) flow. The US patentapplication entitled “System and Method for Providing Rapid Rerouting ofReal Time Multi-media Flows,” by MeLampy, et. al., filed on Jul. 23,2001, having Ser. No. 09/911,304 (hereinafter “the '304 patentapplication”), the disclosure of which in hereby incorporated byreference in its entirety, teaches use of multi-media routers forguiding the resulting RTP flows selected and processed by the sessionrouter through certain thresholds. Therefore, the combination of theabove-mentioned '256 and '304 patent applications creates a high-qualityborder between various IP networks. Without these mechanisms, datapackets would flow whichever way networks would allow.

FIG. 1 is a block diagram that illustrates a communication network 102,wherein the use of session routers (SRs) and multi-media routers (MRs)is demonstrated, for implementation of the present encryption system. Asshown by FIG. 1, a first carrier network 112 comprises a first SIP phone114, such as those produced by Pingtel of Massachusetts, U.S.A., a firstsession router 116, and a first multi-media router 118. A second carriernetwork 132, which is connected to the first carrier network 112 via anInternet 122, comprises a second SIP phone 134, a second session router138, and a second multi-media router 136. It should be noted that anydevice, SIP or non-SIP, may be included within the first and secondcarrier networks 112, 132 that requires communication between thenetworks 112, 132. Other RTP data sources include, but are not limitedto, integrated access devices (IAD), VoIP gateways (Cisco AS5300, SonusGSX), and multi-media sources (PCs, IP-PBXs). Further, communicationbetween the networks 112, 132 may instead be provided via a wide areanetwork (WAN) or local area network (LAN). Also, the Internet 122, mayinstead be a data network domain since the multi-media routers 118, 136are utilized between two domains within the Internet 122.

Alternatively, a router, such as, but not limited to, a border router,may be located between the first and second multi-media routers 118, 136to assist in communication between the first and second carrier networks112, 132. Communication from the first SIP phone 114 to the second SIPphone 134 may instead be provided by the first and second multi-mediarouters 118, 136, as is further explained in detail hereinbelow. Itshould be noted, however, that an additional router, such as a borderrouter, is not necessary in providing communication between the firstand second carrier networks 112, 132. It should also be noted thatcommunication may be from a session router, directly to the Internet122, and not through the multi-media routers 118, 136.

The first and second session routers 116, 138 provide session initiationprotocol (SIP) and telephony routing over IP (TRIP) protocol support asdescribed in detail by the presently pending application titled “Systemand Method for Assisting in Controlling Real-Time Transport ProtocolFlow Through Multiple Networks,” by MeLampy et. al., having Ser. No.09/844,204, and being filed on Apr. 27, 2001, the disclosure of which isincorporated herein by its entirety.

Additional multi-media routers may be provided between the firstmulti-media router 118 and the second multi-media router 136. FIG. 2 isa block diagram illustrating the use of three multi-media routersinstead of two, in accordance with an alternate embodiment of theinvention. As such, the first multi-media router 118, located within thefirst carrier network 112, communicates with a third multi-media router137, via the Internet 122. The third multi-media router 137, in turn,communicates with the second multi-media router 136, within the secondcarrier network 132, via the Internet 122.

Communication between two multi-media routers is herein referred to as acommunication segment, wherein communication segments are defined asinter-multi-media router RTP flows. Therefore, if an RTP flow is from asource, such as the first SIP phone 114, in FIG. 1, to a firstmulti-media router, to a second multi-media router, and finally, to adestination, such as the second SIP phone 134, three communicationsegments exist. The first communication segment is from the source tothe first multi-media router; the second communication segment is fromthe first multi-media router to the second multi-media router; and thethird communication segment is from the second multi-media router to thedestination. Of specific interest with reference to the presentencryption system is the second communication segment, namely, from thefirst multi-media router to the second multi-media router. It should benoted, however, that encryption in accordance with the present inventionmay be provided between any two endpoints.

The introduction of multi-media routers into the real-time multi-mediaflow forces data packets through a known interface, which may act as anencryption multi-mediator. FIG. 3 is a block diagram furtherillustrating a multi-media router 118, such as the first or secondmulti-media router 118, 136, which may be used for purposes of providingencryption capabilities within the communication network 102. As shownby FIG. 3, the multi-media router 118 comprises a flow qualitymanagement engine 202, a traffic manager 206, a communication interface208, a host processor 212, a network processor 214, input devices 216and output devices 218, all of which communicate within the multi-mediarouter 118 via local link 219. Each of the above-mentioned are describedin detail in the presently pending patent application entitled, “Systemand Method for Providing Rapid Rerouting of Real Time Multi-MediaFlows,” filed on Jul. 23, 2001, and having Ser. No. 09/911,304.

Specifically, the traffic manager 206 is preferably used for measuringand enforcing IP session data flow rates, or traffic, for providingtraffic measurement. An example of a commercially available trafficmanager 206 is an NPX5700 traffic manager sold by MMC Networks locatedin California, USA. Essentially, the traffic manager 206 measures thenumber of data packets that flow through the communication interface208. The traffic manager 206 works in concert with the network processor214 such that once a forwarding decision is made, the traffic manager206 queues the received packet into its respective IP flow andassociated priority.

As is known in the art, the traffic manager 206 comprises a memory fortemporarily storing received data packets. From an inbound perspective,the multi-media router 118 is able to monitor RTP data flows and enforcemaximum data rates by either dropping packets or marking them aseligible for discarding if they are outside a bandwidth allocated forthe data flow. The traffic manager 156 may also be instructed by asession router to accept a specific amount of data in accordance with anallocated bandwidth and bit rate. Therefore, if data is received at ahigher bit rate than allowed by the session router, the data received atthe higher bit rate is not transmitted. It should be noted that thecharacteristics specified by the session router may instead beprogrammed directly into the multi-media router 118 without using thesession router.

The flow quality management engine 202 provides translation serviceswithin the multi-media router 118, quality measurement services, anddetection and correction of upstream and downstream failures. Thetranslation services performed by the flow quality management engine 202within the multi-media router 118 comprise the capability to translate asource address, destination address, source port, destination port orany combination of these fields. The multi-media router 118 is alsocapable of removing and/or inserting a multi-protocol label switching(MPLS) tag in the IP header of a multi-media data flow packet. Inaddition, the multi-media router 118 is capable of inserting ormodifying a diffserv codepoint located within the IP header of thepacket, which, as is known in the art, is used to modify priority of thedata packets.

The quality measurement services provided by the flow quality managementengine 202, within the multi-media router 118, are provided on a perflow basis, wherein a multi-media data flow is defined by a source IPaddress, a destination IP address, a source port, and a destinationport. Quality measurement preferably comprises maintaining currentstatistics for the flow within the network processor 214, as well asaggregate and min/max statistics for the flow where applicable. Examplesof statistics that may be collected include latency, jitter and packetloss for a pre-defined window of time. It should be noted that thewindow can be identified via the session router or the multi-mediarouter 118. Aggregate statistics may include transmitted packets,dropped packets and duplicate packets. Minimum and maximum statistics,otherwise referred to as boundary statistics, may also be collectedwhich may include latency, jitter and packet loss per window of time.The flow quality management engine 202, within the multi-media router118, also provides the detection and correction of upstream anddownstream failures in the transmission of RTP data packets

The host processor 212, similar to the traffic manager 206, providesdetection and correction of upstream and downstream failures. Methodsused by the host processor 212 to detect and correct upstream anddownstream failures in the transmission of RTP data packets include, butare not limited to, the use of link failures and external managementevents

A memory unit 222 is also located within the multi-media router 118.Encryption software 224 is stored within the memory unit 222 forproviding logic to be performed in accordance with the presentencryption system. FIGS. 4 and 5, described hereinbelow, provide flowcharts illustrating functionality performed by the present encryptionsystem in accordance with the encryption software 224 of FIG. 3.

FIG. 4 is a flow chart illustrating operations performed by the presentencryption system to provide encryption of multi-media data packetstransmitted within RTP flows. With regard to FIG. 4 describedhereinbelow, a block represents a module, segment, or portion of code,which comprises one or more executable instructions for implementing thespecified logical function(s). It should also be noted that in somealternate implementations, the functions noted in the blocks may occurout of the order noted. For example, two blocks shown in succession mayin fact be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved.

As shown by block 302, sequence numbers within the RTP flow are randomlyshuffled. In accordance with the preferred embodiment of the invention,a sequence number is assigned to each RTP multi-media data flow packetwithin an RTP flow such that when an RTP multi-media data flow packet isreceived, the associated sequence number may be determined.Randomization code is utilized to provide random shuffling of thesequence numbers. Preferably, the random shuffling is algorithmicallypredictable if a key to the randomization code is known. Therefore,since the randomly shuffled sequence numbers are algorithmicallypredictable if the key is known, the sequence numbers really are notrandomly shuffled but are instead, pseudo-randomly shuffled.

The following provides an example of code that may be utilized toprovide randomization of sequence numbers that are used to provideencryption of multi-media packets. It should be noted that the following“C” code, which may be written on a Linux platform, is provided as anexample of code that may be used to randomize, and therefore, is notintended to be a limitation on code that may be used for randomizationpurposes.

EXAMPLE

#include <stdlib.h> main( ) { int salt = 89; int sequence = 1; srand(salt); for (sequence = 1; sequence <= 10; ++sequence) {printf(“sequence %d=%d\n”, sequence, rand( )); } }

When executed, this code produces the following output:

sequence 1=1888747329

sequence 2=1601588182

sequence 3=1967410106

sequence 4=1009646503

sequence 5=230365314

sequence 6=1353059132

sequence 7=1304719048

sequence 8=497992519

sequence 9=346418450

sequence 10=17439427

Therefore, a one to one mapping of the sequence numbers in order may bemade to random numbers. For instance, 1304719048 maps to 7, and 7 mapsto 1304719048.

Applying this mapping to the step of randomly shuffling sequence numberswithin an RTP multi-media data flow (block 302), the first RTPmulti-media data flow packet has a sequence number 1888747329 (whichmaps to 1), the second packet has a sequence number 1601588182 (whichmaps to 2), and so on. Using this algorithm, the receiving side mayproduce a sequence of expected sequence numbers and restore them. As anexample, a sender that is transmitting an original sequence number of 1(or a salt value of 1) may replace the original sequence number with anencrypted sequence number of 1888747329. The encrypted sequence numberof 1888747329 may then be transmitted to a receiving side. Upon receiptof the encrypted sequence number, the side receiving may restore to theoriginal sequence number of 1. Therefore, if the starting value,otherwise referred to as the original value, is known, an encryptedsequence number can be produced and decoded. However, if the originalsequence number is not known, the encrypted sequence can not beanticipated and later decoded.

In accordance with an alternate embodiment of the invention, a series oforiginal sequence values may be utilized. As a result, a series ofencrypted sequence numbers are utilized which makes decryption much lesslikely. Therefore, if there are multiple flows of multi-media datapackets (RTP data packets) being transmitted from the first multi-mediarouter to the second multi-media router, each multi-media packet mayhave a separate original sequence value, thereby providing excessivescrambling of the data associated with the multi-media data packet.

Returning to FIG. 4, a destination port address for the multi-media datapacket may also be encrypted (block 304). Preferably, an IP address isused to enable delivery of a multi-media data packet to a multi-mediarouter. As is known in the art, an IP address comprises an address of adestination device, as well as a destination port address within thedestination device. With reference to the present encryption system, theIP address identifies a destination multi-media router and a destinationport address within the same multi-media router. Since the IP address isused to deliver the multi-media data packet to the destinationmulti-media router, it is possible to encrypt the destination portaddress to provide further difficulty in decrypting transmittedmulti-media data packets.

In accordance with the preferred embodiment of the invention, the portaddress number is encrypted so that it may be restored in the future, asis described in detail hereinbelow. Following the above providedexample, a salt value, or original sequence number, of eighty-nine (89)has been assigned as an identifier of the group of ten sequence numbersthat may be used for encryption purposes. A first method of providingencryption of the port address number is by having a repeating sequenceof numbers for the destination port address number. In accordance withthe present example, the sequence of numbers starts at 1888747329 andprogresses through the tenth number 17439427. It should be noted thatthe length of the sequence number may be variable.

In accordance with the first method, the port address number may bebased on either the salt value, which in the present example is 89, orit may be determined from the sequence numbers. An example of utilizingthe salt value follows. If the salt value is 89, the sequence numbersare determined to be 1 through 10, and the sequence numbers arerepeated, the port number is 89 (the salt value) multiplied by 10 (thelength of the sequence), or 890. In addition, if there is more than onemulti-media data flow, the random port address numbers are verydifficult to detect without knowledge of the salt value.

As shown by block 306, re-sequencing of the multi-media data packets isthen performed within an appropriate jitter buffer size. A jitter bufferis typically implemented in voice gateways to compensate for fluctuatingnetwork conditions. The jitter buffer is a packet buffer that holdsincoming multi-media data packets for a specified time before forwardingthem for decompression. This process has the effect of smoothing themulti-media data packet flow, thereby increasing the resiliency of acompressor/decompressor (CODEC) to packet loss, delaying packets, andproducing other transmission effects. However, the downside of thejitter buffer is that it can add significant delay. The jitter buffersize is configurable, and can be optimized for given network conditions.The jitter buffer size is usually set to be an integral multiple of theexpected packet inter-arrival time in order to buffer an integral numberof multi-media data packets.

Re-sequencing of multi-media data packets allows multi-media datapackets to be transmitted from a first multi-media router to a secondmulti-media router in a random manner within a small repeating window.In accordance with the abovementioned example, multi-media data packetsmay be transmitted, and arrive, in a normal order such as 1, 2, 3, 4, 5,etc. However, in accordance with the re-sequencing of multi-media datapackets, the multi-media data packets may be transmitted in any orderdesired, including, but not limited to, 2, 5, 4, 1, 3, etc. Thisre-sequencing prevents anyone from assembling the multi-media datapackets in the order sent, disregarding the sequence number, and beingable to decipher the communication.

As shown by block 308, bit manipulation within the multi-media datapacket is performed to provide further encryption of the multi-mediadata packets. An example of bit manipulation may be performed usingbitsize operations that are restorable, such as, but not limited to,the˜operator (newbits=˜oldbits). As is known in the art, the˜operator isa negation operator. Therefore, every “1” bit becomes a “0” bit, andevery “0” bit becomes a “1” bit. As an example, the binary number10011100 becomes 01100011.

Other bitsize operations may include shifting bits to the left, as isillustrated in the examples hereinbelow.

EXAMPLE

Newbits=(oldbits & 0x0f)<<4∥(oldbits & 0xf0>>4)

This example essentially swaps bits 0-3 with bits 4-7.

In addition, bytes may be swapped in an algorithmic fashion based on amapping sequence rendered from a random number. As an example, assumingthat there are 256 bytes in a multi-media packet, the bytes may beswapped or mixed based on a sequence rendered from 1 to 256 whereduplicates are skipped. Therefore, any salt value may be used, and whenthe random number is generated it is modulo divided by 256. The sequenceis then run until there are 256 unique numbers. If a duplicate isencountered during running of the sequence, it is skipped.

Thus a pattern emerges such as the pattern shown hereinbelow.

1=23

2=220

3=19

4=113

5=78

.....

256=21

This sequence can be created very efficiently. As mentioned hereinabove,if a duplicate is encountered, the duplicate is skipped. Thus, if asecond 19 is generated when sequence 15 is being computed, the 19 isskipped, and a new call to a random number generator generating thesequence is called so that the sequence will be complete.

The following provides a detailed example of sequencing random numbers.Assuming use of the sequence numbers provided in the example illustratedhereinbelow, if a sequence of numbers from 0 to 4 is desired to swapbytes, the following steps are performed. The random number is taken anddivided by the number of sequence numbers desired (in this example 5)(1888747329/5=377749465, remainder=4). The remainder is then recordedafter division. The process is then repeated for the entire sequenceresulting in the following.

sequence 1=4

sequence 2=2

sequence 3=1

sequence 4=3

sequence 5=4

sequence 6=2

sequence 7=3

sequence 8=4

sequence 9=0

sequence 10=2

A list is assembled in order having no duplicates and using the sequenceof numbers shown above (4, 2, 1, 3, 0). It should be noted thatsequences 5, 6, 7 and 8 were dropped since they were duplicates untilfive unique integers from 0-4 were obtained.

To swap the bytes in this order, the new sequence is used as indexpositions in a “byte swapping” scheme.

newarray[4]=oldarray[0]

newarray[2]=oldarray[1]

newarray[1]=oldarray[2]

newarray[3]=oldarray[3]

newarray[0]=oldarray[4]

To restore the data to its original form, the following “reverse”translations are performed.

oldarray[0]=newarray[4]

oldarray[1]=newarray[2]

oldarray[2]=newarray[1]

oldarray[3]=newarray[3]

oldarray[4]=newarray[0]

An example of how the generator may be algorithmically coded follows.

EXAMPLE

#include <stdlib.h> main( ) { int salt = 89; int sequence = 0; intresults[256]; srand(salt); for (sequence=0; sequence < 256; ++sequence){ results[sequence] = rand( ); /* Get the next random number */ for(i=0; i < 256 && I < sequence;++i) {/* See if the sequence is in thelist */ if (results[sequence] == results[i]) { --sequence; /* Already inthe list, skip this one */ break; } } } for (sequence=0; sequence <256;++sequence) { /* Display the list */ printf(“Sequence = %d, New sequencenumber=%d\n”, sequence, results[sequence]); } }With this coded logic, all 256 bytes of the multi-media data packet maybe encrypted before leaving the first multi-media router, and berestored upon arrival at the second multi-media router.

As mentioned hereinabove, any single encryption step described by FIG. 4may be used to provide encryption of multi-media data packets. Inaddition, any combination of the above-mentioned encryption steps may beused to provide encryption of multi-media data packets. Further, theabovementioned operations described by the flowchart of FIG. 4 may beperformed by a programmed controller, or any other hardware for thatmatter, instead of, or in addition to being performed in accordance withsoftware.

It should be emphasized that the above-described embodiments of thepresent invention, particularly, any “preferred” embodiments, are merelypossible examples of implementations, merely set forth for a clearunderstanding of the principles of the invention. Many variations andmodifications may be made to the above-described embodiment(s) of theinvention without departing substantially from the spirit and principlesof the invention. All such modifications and variations are intended tobe included herein within the scope of this disclosure and the presentinvention and protected by the following claims.

1. A method for encrypting muli-media data flow packets, comprising thesteps of: receiving a series of multi-media data flow packets; storingthe series of multi-media data flow packets in a jitter buffer;pseudo-randomly shuffling a destination address of each of themulti-media data flow packets; re-sequencing the series of multi-mediadata flow packets into a pseudo-random order; and transmitting eachmulti-media data flow packet in the re-sequenced series in there-sequenced order.
 2. The method of claim 1, wherein said re-sequencinguses a randomization code that is algorithmically predictable if a keyto said randomization code is known.
 3. The method of claim 1, furthercomprising the step of performing bit manipulation within said firstmulti-media data flow packet.
 4. The method of claim 3, wherein saidstep of performing bit manipulation is performed by using a bit-sizeoperation that is restorable.
 5. The method of claim 4, wherein saidbit-size operation comprises negation.
 6. The method of claim 1, whereinsaid destination address is a destination port address.
 7. A computerreadable storage medium having a program for encrypting multi-media dataflow packets, the program performing the steps of: receiving a series ofmulti-media data flow packets; storing the series of multi-media dataflow packets in a jitter buffer; pseudo-randomly shuffling a destinationaddress of each of the multi-media data flow packets; re-sequencing theseries of multi-media data flow packets into a pseudo-random order; andtransmitting each multi-media data flow packet in the re-sequencedseries in the re-sequenced order.
 8. The computer readable medium ofclaim 7, wherein said re-sequencing uses a randomization code that isalgorithmically predictable if a key to said randomization code isknown.
 9. The computer readable medium of claim 7, the program furthercomprising logic for performing the step of performing bit manipulationwithin said first multi-media data flow packet.
 10. The computerreadable medium of claim 9, wherein said step of performing bitmanipulation is performed by using a bit-size operation that isrestorable.
 11. The computer readable medium of claim 10, wherein saidbit-size operation comprises negation.
 12. The computer readable storagemedium of claim 7, wherein said destination address is a destinationport address.
 13. A system for encrypting muli-media data flow packets,comprising: a transceiver; software defining functions to be performedby the system; and a processor configured by said software to performthe steps of: receiving a series of multi-media data flow packets;storing the series of multi-media data flow packets in a jitter buffer;pseudo-randomly shuffling a destination address of each of themulti-media data flow packets; re-sequencing the series of multi-mediadata flow packets into a pseudo-random order; and transmitting eachmulti-media data flow packet in the re-sequenced series in there-sequenced order.
 14. The system of claim 13, wherein saidre-sequencing uses a randomization code that is algorithmicallypredictable if a key to said randomization code is known.
 15. The systemof claim 13, wherein said destination address is a destination portaddress.
 16. A method of encrypting a series of multi-media data flowpackets, comprising the steps of: receiving a series of multi-media dataflow packets belonging to a first flow, each packet in the series havinga port address that is the same as the port address of the other packetsin the series; generating a pseudo-random sequence of numbers, thesequence of numbers associated with the port address; replacing the portaddress in each packet with the product of a corresponding number in thesequence of numbers and the size of the sequence; and transmitting eachpacket to a receiver.
 17. The method of claim 16, wherein the generatingstep uses a randomization code that is predictable if a key to therandomization code is known.
 18. The method of claim 17, wherein the keyis known to the receiver.
 19. The method of claim 16, wherein the sizeof the sequence is known to the receiver.
 20. The method of claim 16,wherein the port address comprises a destination port address.